The invention relates to services accessible via a subscription in a communication system, and particularly to a subscription having an account and a predetermined limit. Examples of such subscriptions are a prepaid subscription and a postpaid subscription with a limit indicating the maximum allowed amount to be billed. A postpaid subscription refers to a subscription which is charged in arrears.
Mobile communications systems have been developed in order to free people from fixed telephone terminals without hindering their reachability. Often the mobile communications network is an access network providing a user with wireless access to external networks, hosts, or services offered by specific service providers. The development of packet-switched services, such as the General Packet Radio Service GPRS in the Pan-European mobile communications system GSM (Global System for Mobile Communications), allowing packet data transmission between mobile data terminals and external data networks, enables the development of a variety of services. One example of such services are different WAP (Wireless access protocol) services via which service providers can provide services free of charge, i.e. services the usage of which is paid by the service provider and/or an advertiser.
Along with the mobile communications systems, a variety of services provided through mobile stations have also been developed. One example of new services becoming increasingly popular is a prepaid subscription. The prepaid subscription involves no billing in arrears but the account of the prepaid subscription is charged in real-time during calls. The prepaid subscription can usually be used for chargeable connections or services until the credit in the subscription's account runs out, in other words until the prepaid amount has been exhausted. Another service similar to the prepaid service is a postpaid service with a limited bill, i.e. a postpaid subscription with a limit indicating the maximum allowed amount to be billed. It differs from the prepaid subscription in that the subscription allows access to chargeable connections or services until the bill reaches the limit.
Both of these services are expected to be widely popular also for packet switched services. The problem related to the arrangement described above is that when the subscription does not allow access to chargeable calls, it does not allow access to services free of charge either. The prepaid subscription involves another problem, too. Usually, the subscriber to the prepaid subscription, or someone else, can deposit more money in the subscription's account. However, when the prepaid amount has been exhausted, money can not be deposited via the prepaid subscription.